This invention relates to a novel enclosure for a loudspeaker which results in improved loudspeaker performance. It also relates to an improved waveform energy reflector which may be utilized in combination with the loudspeaker enclosure, which combination both gives improved loudspeaker performance and disperses sound more accurately. In particular, the present invention increases sustain characteristics of sound or other waveform energy produced with its use. It further produces a shear wave to disperse sounds or other energy produced with less distortion of the sounds.
As used herein, the term "sustain" refers to non-interferring, usable energy wave impulses that enhance and effectively prolong the initial frequency pressures developed by a selected or specific waveform transducer, such as a speaker cone, without distorting previous or subsequent frequency responses. The term "shear wave" refers to a wave in an elastic medium which causes an element of the medium to change its shape without changing its volume. As applied to a loudspeaker, the enclosure and speaker of this invention produces a shear wave as its primary waveform by reflecting and dispersing sound waves produced by the speaker. Air is the elastic medium and the enclosure and reflector are the shape changing means. Due to the shape of the enclosure and reflector of this invention, the shear wave is produced without substantial distortion of the sound. The term "sinusoidal" refers both to a waveform that can be described by a simple sine function and to the combination of simple sine function waveforms with more complex waveform patterns to give a complex sinusoidal waveform.
In my prior U.S. Pat. Nos. 3,819,005 and 3,819,006, issued June 25, 1974, structures are described in which enclosures forming a spherical chamber behind a loudspeaker and a reflector positioned in front of the loudspeaker are provided. The structures described in those patents have now achieved a degree of acceptance as a result of their ability to provide improved sound quality at large outdoor public gatherings, including outdoor performances of symphony orchestras and large choral groups. While the present invention also provides a chamber behind the speaker and a reflector in front of the speaker, it has now been determined that further improvements in sound quality may be achieved by constructing the chamber and reflector in a different manner.